Shoom Review – A New iPad Synth With Plenty Of Va Va Voom!


A drive through the generations

It’s probably apt that Shoom is also the name of an Eighties Acid House club. Admittedly while dreading another Sixties Hippy Dippy noise generator, I had mentally written off Shoom. How wrong I was! After all, Shoom is made by Yuri Turov, the developer of the rather excellent Xynthesizr. O me of little faith.

Don’t get me wrong, Shoom can wallow in all the eccentricities of noise generation, yet where some limit control, Shoom showers you with the feeling of – Look what I created! It’s this feeling of being able to creatively span genres that marks Shoom up above your average app – multi-faceted and with more hiding under the hood than a souped-up street racer.

So what has Yuri Turov stashed under the hood that has got many excited to give Shoom a test drive? Does Shoom span the generations between sixties experimental, the emergence of eighties dance and our modern ménage of genres? Let’s take a little trip…

The essence of a good automobile

At the heart of Shoom is 3x two oscillator subtractive synths powering an expressive XY pad – a combination which helps Shoom carve out its own niche. So while similarities to other apps are apparent, Shoom has more to offer than maybe first apparent. Shoom’s power comes from a symbiotic relationship between its synth engine and its wonderfully touch-centric interface (of which we will lovingly polish later).

Those that wish to play the presets are presented with 60+ to get going (more on these later), but hey, these are synths and with this in mind, let us first see what the synth engine offers those that want to get their hands dirty. After all, without a powerful engine, this shiny car is not going anywhere fast!


What power do you have under the hood?

Shoom has a selectable voice count, with 30 being the maximum shared between the 3 synths. Voice stealing can be set to either replace the longest note or ignore a new note. I will admit to wishing for more options here (to prioritise the 3 synths for voice stealing or last note steal), but in use, I found the 30 voices to be more than adequate in most real use scenarios.

You may choose which of the 3 synths you currently control via a three-way selector centre top of the screen. Each of the synths has a corresponding colour to the on-screen notes – a nice touch.

The three selectable synths have tabs for Oscillator, Envelope, Modulation, Effects and Control at the top right of the screen:

Osc Page

Each oscillator has a choice of four basic waveforms (Sine, Triangle, ramp up Sawtooth and Square), with pulse width modulation for the Square wave. Octave, semitones and cents dials control the pitch of each oscillator. Oscillator 2 has an additional knob controlling the amount oscillator 1 is modulated by the output of oscillator 2 (independent of the level of oscillator 2 in the mixer), so some basic Frequency Modulation is covered.

The oscillator section is completed with a knob controlling the colour of the noise generators output and a 3 knob mixer (Osc 1, Osc 2 and Noise).


Env Page

Consisting of Amp and Filter envelopes either side of a 4 pole (24db/octave) low pass filter. Each of the envelopes consists of classic ADSR (attack, decay, sustain, release) design. The Amp envelope is based on a classic analog design where the decay and release knobs set rate rather than time value (duration for each is dependent on the sustain value set). A volume level and variable slope knob (envelope curve) round out the Amp envelope. The Filter envelope is pretty much identical except for the depth control knob. This has positive or negative effect on the filter cutoff (zero is no effect).

The choice of 4 pole (24db/octave) low pass filter seems a fair choice, if a little on the ‘safe’ side in this day of multimode and ‘exotic’ filters in software. While having 3 synths to play with helps towards some sound design, I can’t help but wish for the inclusion of a high pass option. On the positive side, keeping the options simple does keep the interface from becoming cluttered.

Single choice of filter aside, what really puts the Shoom into this engine is the Modulation possibilities…


Mod Page

Modulation – the fuel injection system of many a synth engine. I must give a nod of approval to the developer here for giving each synth two LFOs (low-frequency oscillator). This is one area where many low-cost hardware synths used to be lacking (back in the day).

Both of the LFOs have the same features, beginning with the choice between Trigger and Global modes. Global mode has all voices using the same LFO. Trigger however, gives each of the synth voices its own LFO, very handy in conjunction with the note Hold function. While the settings for each notes LFO will be identical, having them trigger individually for each note while Hold is activated, was key to many rhythmic effects – even managing to create a passable church bell ringing session. As the manual suggests, try applying modulation to LFO frequency while in trigger mode for an interesting effect.

The next option gives the ability to Sync the LFO frequency to Tempo (set top left of the screen). This is an on or off option, with ‘off’ setting releasing the LFO frequency value to be set freely between 0.02 to 40hz by the Frequency knob. The ‘on’ setting showing the frequency as a subdivision from 8 whole notes to 1/64th.

Phase and Fade In, allow you to set the starting point of the wave and the time it takes to reach full amplitude after a note is pressed, respectively. Speaking of the LFO waveforms, a generous 9 are supplied, including: Sine, Triangle, up ramp Sawtooth, down ramp Sawtooth, two ‘exponential decay types, Square, and two varieties of Random (sample and hold / continues linear). I think you will agree many LFO ‘tricks’ will be covered by these options!

The three final LFO knobs are selectable between the choice of 12 different modulation destinations – these include: Osc 1+2 pitch, Osc 1 pitch, Osc 2 pitch, Osc 1 pulse width, Osc 2 pulse width, Osc 2-1 FM depth, Osc 1 level, Osc 2 level, Noise level, Amp level, Filter cutoff, and last but not least, the frequency of the other LFO.

Y-Axis knobs (3 available) give all of the above destinations plus depth for each of the LFOs. Well ‘Pimped up’ may be one way of describing this rad mobile, yet take a look at the pictures above and below. Shoom takes options further still by giving access to CC (continuous controller) values. Want more LFOs? Use another app to add them! Each synth can have its CCs programmed and received on any MIDI channel.


Effects Page

Shoom’s developer has wisely (I believe) chosen not to throw every known effect inside its engine. A choice of Delay and Reverb per synth seem more than fair when knowing that Shoom is Audiobus and IAA compatible. I must say though, that as often is the case, no individual outs (a pet peeve of mine) are supplied. So, while the choice of effects is probably the most logical one, I personally would have sacrificed the reverb for a chorus / flanger and added reverb globally in a host.

The delay is admittedly one of my favourite effects and while the one supplied is not of the lovely squelchy tape delay varieties, it does the job well enough. With a range of 5-3000 ms, either linked or separate for left and right channels – one to infinite repeats and syncable to the main tempo setting. Yes, I did have a hankering to connect up my tape delay to a single part, so please Yuri Turov – please consider separate audio outs or record out as separate stems.

Reverb again is of decent quality and has a fair amount of control compared to many ‘onboard’ synth varieties. Predelay and Mix take care of how soon and to what amount you affect the dry signal and Size is pretty self-explanatory. Decay and Hi – Lo cut-offs are also supplied to control the length of the reverb tail and cut frequencies pre-reverb respectively. Dampening attempts to simulate the natural absorption of high frequencies and the amount of modulation is controlled by the Mod knob. Again, both effects can be switched off to reduce the load on the CPU.


Control Page

The control page allows you to set how the current synth responds to your playing on the pad, of which I will describe after this section. The pad is essentially the transmission of our car and this page sets how we would like it to affect each synth engine. Here I would have like to have seen a way to link synth engines together for fast use of two or more sounds with one touch – maybe a feature that could be added later?

Pitch Lock gives us the ability to lock to a certain pitch, so switch this off if you want to go into Theremin territory! Snap lets you snap to a pitch at the note on point and with Pitch Lock off, you can then slide you note up and down your chosen scale. Further to this, the Snap section lets us control Glide amount and Legato on or off.

X/Y Pad – Crank it into gear!

As our transmission is controlling our engine, our flash steering needs to be spot on to give us control of this mighty beast of an engine. Lets drive…

The X/Y pad takes up the majority of the screen and has the full 20hz to 20khz audio range along its X axis, with a handy slider showing where each finger press is along this range. Going up from the X axis is a series of coloured lines expressing the chosen scale. Each scale can be chosen from a healthy list of 43! You may also design your own. Tuning of each scale can then be selected from a list of 18, again with the ability to design your own – really impressive for those that would like to dabble in alternative tunings and scales.

The Y axis, as discussed earlier, is there for you to set a choice of 3 out of 15 modulations. I would have liked some quick access buttons down the left-hand side of the Y axis, to quickly switch some modulations on or off.

Bear in mind, we have 30 voices shared to 3 seperate synth engines to play with. With the use of the Hold function, an awful lot can be happening on screen at once. Thankfully single held notes may be released with a double tap of their circle, but what is probably more helpful is two buttons to the bottom right of the screen – one of which releases all held notes of the currently selected synth, and the other that releases all notes – very handy!


Let’s buff up that paintwork!

To my mind, what makes Shoom so comfortable to drive is how the X/Y pad and its controls are designed to work with the synth engines. Each synth engine is instantly selectable by the bank of three colour coded buttons at the top middle of the screen. These colours correspond to the circles each finger press makes on the screen. A solid circle means the note is held. An empty circle means the note will release when you lift your finger. The note Hold button is at the lower left of the screen and quick release of any note is only a couple of taps away.

All pages are pretty accessible and control of each sound means that the 3 synths and the player can quickly gain a synergy that makes it truly feel like you are creating. I find with too many apps that can be used to make ambient sounds, that they feel more in control than the player at times – not the case with Shoom.

The 60+ presets bundled are a healthy range from the weird and wacky to the more conservative favoured by this slightly grey-haired reviewer. Theremin territory is covered as expected. Percussive and ambient – check! Haunting and film score – you got it! An all round good set to get you started. Yet, as I often say, synth knobs are made to be twiddled – get twiddling!

Conclusion – Shoom in the Showroom

While I may have mentioned a few areas where I would like changes or additions, I can’t help with being very impressed with the design Yuri Turov has put into Shoom. This really is an A-class car and not an also-ran.
Yes, I will sum up with some ‘Class Design’ and some ‘Pimp My Ride’ point below, but at the end of my test drive it is a case of car bought and would recommend you buy too. Shoom… plenty of Va Va Voom!

Class Design:

  • Wonderful synergy between interface and synth engine.
  • Expressive tones and playability.
  • You want a scale and tuning – you got it!

Pimp My Ride:

  • Multiple audio outs or record stems.
  • Recordable X/Y pad automation and arpeggiator.
  • MIDI note input and multi-synth note connection.

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